Ministry of Jal Shakti
Water Level In Rivers
There are two types of rivers in the country, perennial rivers and non-perennial rivers. In perennial rivers, water remains available throughout the year, while non-perennial rivers are rain fed rivers in which water flows mostly during the rainfall period only. Flow in the rivers is a dynamic parameter and depends on many sub-parameters such as rainfall, its distribution pattern, duration and intensity in the catchment, health of catchment area, vegetation and withdrawals/utilization of water.
CWC carries out hydrological observation on rivers across the country. The decadal average flow of the last two decades of terminal sites of 13 rivers does not indicate any major increasing or decreasing trends.
The study "Reassessment of Water Availability in India using Space Inputs" has been carried out by Central Water Commission  in 2019. As per the study, the average annual water resources of the 20 basins of the country has been assessed as 1999.20 Billion Cubic Meters . The average annual water availability of any region or country is largely dependent upon hydro-meteorological and geological factors. However, water availability per person is dependent on population of the country and the per capita availability of water is decreasing due to increase in population.
As per the National Commission on Integrated Water Resources Development  Report-1999, water requirement of the country for Low and High Demand scenarios for the year 2050 is 973 BCM and 1180 BCM respectively.
As per study titled “Reassessment of Water Availability in India using Space Inputs, 2019” conducted by Central Water Commission in collaboration with NRSC, the average annual water resources availability in the country is assessed as 1999.20 BCM. It is estimated that owing to topographic, hydrological and other constraints, the utilizable water is 1,126 BCM.
Water being a State subject, steps for augmentation, conservation and efficient management of water resources are primarily undertaken by the respective State Governments. In order to supplement the efforts of the State Governments, Central Government provides technical and financial assistance to them through various schemes and programmes.
Ministry of Environment, Forest & Climate Change  in the Standard Terms of Reference  for conducting the Environmental Impact Assessment  studies for any proposed River Valley and Hydroelectric Project have mentioned the norms for release of environmental flows, which is 30% in monsoon, 20% in lean season and 25% in non-monsoon & non-lean season to be followed corresponding to flow of 90% dependable year. These norms along with the site specific requirements for environment flow releases as per the studies are then stipulated in the Environment Clearance  letter for compliance.
Government of India, vide Notification dated 9th October, 2018 has notified minimum environmental flows to be maintained in river Ganga from its origin to Unnao in Uttar Pradesh.
Government of India, in partnership with States, is implementing Jal Jeevan Mission  to make provision of potable tap water supply to every rural household of the country at the service level of 55 litre per capita per day by 2024. For ensuring tap water supply in drought-prone & water-scarce areas with inadequate rainfall or dependable ground water sources, provisions have been made under JJM for bulk water transfer from long distances and regional water supply schemes. In addition, provisions have been made for source recharging, viz. dedicated bore well recharge structures, rain water recharge, rejuvenation of existing water bodies, etc., in convergence with other schemes such as MGNREGS, Integrated Watershed Management Programme , 15th Finance Commission tied grants to RLBs/ PRIs, State schemes, CSR funds, etc.
Government of India has launched Centrally Sponsored Scheme of AMRUT 2.0 on 1st October, 2021 to provide universal coverage of water supply in all statutory towns in the country. AMRUT 2.0 focuses on making cities water secure through recycle/ reuse of treated sewage, rejuvenation of water bodies and water conservation.
The Government of India formulated a National Perspective Plan  of interlinking of rivers for transferring water from surplus basins to deficit basins/areas in 1980. National Water Development Agency  has identified 30 links  for preparation of Feasibility Reports/ Detailed Project Reports under Inter-linking of Rivers Project. However, river interlinking projects are largely dependent on consensus on water sharing between participating States.
Jal Shakti Abhiyan: Catch the Rain  - 2022 has been launched by Hon’ble President on 29.03.2022 in all districts  of the country with the main theme “Catch the Rain, where it falls, when it falls”. The focused interventions of the campaign include  rainwater harvesting & water conservation  enumerating, geo-tagging & making inventory of all water bodies; preparation of scientific plans for water conservation based on it  Setting up of Jal Shakti Kendras in all districts  intensive afforestation and  awareness generation.
This Information was given by the Minister of State for Jal Shakti, Shri Bishweswar Tudu in a written reply in Lok Sabha today.